About RXTE

The HEXTE

The HEXTE consists of two clusters each containing four phoswich
scintillation detectors. Each cluster can ``rock'' (beamswitch) along
mutually orthogonal directions to provide background measurements 1.5
or 3.0 degrees away from the source every 16 to 128 s. Automatic gain
control is provided by using a 241Am radioactive source mounted in
each detector's field of view. The HEXTE's basic properties are:

Energy range: 15 - 250 keV

Energy resolution: 15% at 60 keV

Time sampling: 8 microsecond

Field of view: 1 degree FWHM

Detectors: 2 clusters of 4 NaI/CsI scintillation counters

Collecting area: 2 times 800 cm^2

Sensitivity: 1 Crab = 360 count/s per HEXTE cluster

Background: 50 count/s per HEXTE cluster

Events detected by HEXTE will be processed on board by its own data
system before insertion into the telemetry stream at an average data
rate of 5 kbit/s. Data products include event mode, binned spectra and
light curves, and a burst-triggered event buffer.

The HEXTE was designed and built by the Center for Astrophysics &
Space Sciences (CASS) at the University of California, San Diego. For
more information, see the HEXTE home page at UCSD.